Wood-cutting knife



Feb. 5, 1929.

J. E. ECKERSLEY- woon CUTTING KNIFE Filed Aug. 19, 1927 2 Sheets-Sheet e/ M/ //H V aw Feb.5, 1929.

' J. E. ECKERSLEY LWO D CUTTING KNIFE Filed Aug. 19, 1927 2 Sheets-Sheet 2 broken the grain.

Patented Feb. 5, 1929.

JAMES E. ECKEBSLF-Y, OF ABERDEEN, WASHINGTON, ASSIGNOR ONE-HALF T0,

ALEXANDER POLSON, OF HOQ'UIAM, WASHINGTON. i

WOOD-CUTTING knlrn.

Application .filed August 19, 1927. serial no. 214,184.

In knives heretofore used for veneers and in cutting of wood for shingles, slats, etc, there is one fault that I have noticed and that is this: They have not sufficient draw to cut the fibre of the wood as they pass through, because after the knife has passed through the block of wood there will be seen a number of fibres hanging over the edge of the knife, and this means that this portion of the knife, no matter how sharp it may be, has not cut its way through the wood, but on the contrary has pushed that portion of the knife fibre and all through the wood without cutting and by so doing has I have found thatin the block of wood, by using a knife with a clearance according to my invention, there is not more than one half thousandth of an inch variation in cuttin stock .07 5 whereas in cutting the same lock with the knives heretofore-used that there was from one and one half to two and one half thousandths difference.

This clearance in my improved knife gives 5 the knife free cutting, whereas the knives heretofore used seem to have a binding effeet which prevents them from running freely which results in an unevenness in thickness of the stock.

In the drawings:

Figure l is a bottom plan view of a knife embodying my invention. I

Figure 2 is a vertical central sectional view through Figure 1.

Figure 3 is an enlarged sectional view of v the upper end of Figure 2.

Figure 4 is an enlarged detail sectional. view of the cutting edge of the knife. I

Figure 5 is a bottom plan view of a straight knife embodying my invention.

Figure 6 is an end view of Figure 5.

Figure 7 is an enlarged detail sectional view of the cutting edge portion.

The invention in all of the figures is the same, therefore I willnot describe each detail specifically in Figures 5, 6 and 7, but 1n these figures I will use the same reference numeral, only in Figures 5, 6 and 7 I will add a prime to the numeral used to designate a corresponding part or construction.

The reference'numeral 10 designates a circular or disc like knife embodying my inven} tion, having the cutting edge 11, whlch edge when in action has a shearing effect, which causes the fibre of the material to be cut by shearing instead of being pushed through the material by hanging over the edge of the knife which causes the other fibre or grain on the material to be broken, as herein pointed out.

The knife is provided with suitable bolt or screw openings 13 through which screws may be passed to fasten the knife to a collar mounted on a shaft, the collar and shaft not being shown in the drawings. It will be noted that the screw is to be counter sunk in the knife the purpose of which is to prevent the top of the screw scratching the material while the knife is operating.

As more clearly seen in Figure 4, the cutting edge is designated by the reference numeral 11, while the heel is designated by the reference numberlQ. It will be noted that the cutting edge has one straight side 14, which is the side of the knife next to the block of material operated upon, which side 14 extends a certain distance back to a point 15 where. there is a decidedly sharp drop, the purpose of which is for clearance to relieve friction which produces heat that sets up a tension in the knife.

The cutting edge portion is hollow ground as at 16 on the bottom side of the knife, the purpose of which is to give the stock relief in cutting. Attention is called to the fact that this hollow ground portion does not extend to the extreme cutting edge 11, but ex- V vent-ion embodied in'a straight knife A, and

for corresponding parts in these figures the reference numbers used in theother figures have been primed. p

This invention after commercial tests has been found to overcome the known defects and objections of knives heretofore used, and has glven universal satlsfaction and found to produce a better result.

I am aware that'certam changes may be made in my improved knife without departing from the scope of the appended claims.

What I claim is: 1. In a knife, a cutting edge portion having a flat top face, a bottom. concave face ten minating short of the cutting edge portion, and a cutting edge substantially triangular in cross section and flat throughout its surface area. v

2. In a knife, a cutting edge portion having a fiat top face extending to the cutting edge and terminating away from the cutting edge in an abrupt drop to the plane of the knife body, a bottom face having a concaved face terminating short of the cutting edge 10 in one direction, and extending in the other direction to a point on the knife body back of the abrupt drop ,of the top face.

Intestimony whereof I aflix my signature.

JAMES E. ECKERSLEY. 

